Perpetual calendar



(No Model.) 2lSheets-Sheet H. s. STEVENS,

PERPETUAL CALENDAR.

Patented'Peb. 26, 1895.-

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(No Model.) R 2-Sh'eets-Shet 2.

-H. S,. .STE-/;EN-S.. PERPETUAL ALENDAR, No. 534,726. v Patented Fe 2 ,13

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' HENRY S. STEVENS, OF KEENE, NEW HAMPSHIRE.

PERPETUAL CALENDAR. I

SPECIFICATION forming part of Letters Patent N0. 534,726, dated February 26, 1895.

Application filed October 20, 1894- Serial No. 526,436. (No model.)

To all whom it may concern:

Be it known that I, HENRY S. STEVENS, a resident of Keene, in the county of Cheshire and State of New Hampshire, have invented certain new and useful Improvements in Perpetual Calendars; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to an improvement in calendars and more particularly to such as are known as perpetual calendars,the object of the invention being the production of a simple perpetual calendar, by means of which the day of the week ofa given date can be readily,

With this object in view the invention consists in certain novel features of construction and combinations and arrangements of parts as hereinafter 'set forth and pointed out in the claims.

In the accompanying drawings: Figure 1 is a view showing the appearance of my improved calendar when open. Figs. 2, 3, 4t, 5, 6, 7, and 8 are views of the various tables having the days of the week and years marked thereon. Fig. 9 is a view illustrating 'a modification.

X represents a cover of heavy paper orany other suitable material, in which two books or series of leaves 1, 2, are secured, the book or leaves 1 being secured to the cover at the junction of the sides thereof and having the names of the months and the days of the month produced thereon, two adjacent pages being devoted to each month as illustrated in Fig. 1. The book 1 overlaps all of book 2 except the days thereon which it leaves exposed secured at its center to the inner face of one side of the cover. On each two adjacent pagesof the book 2 a table is produced. In the drawings eachtable is divided into five color spaceA the names of the days of the week are produced. In the column orspace B, figures indicating certain years of one century (the nineteenth, for instance) are produced and in the columns or spaces 0, D, E, figures indicating certain years in succeeding centuries are made. The pages of the book 2 are so disposed that the names of the days of the week on any page can be read with the days of the month on any page of the book 1, as illustrated in Fig. 1. shown in Figs. 2, 3, 4, 5, 6, 7 and 8 and are lettered a, b, c, d, e, f and g, said tables corresponding in number with the number of the days of the week. In column A of table athe days of the week are produced commencing with Saturday and in column A of table I) the days of the week are produced beginningwith Sunday and so on throughout the series of tables so that the days of the week can be read in regular order across the series of tables.

' The same day of the week corresponding with agiven' day of the month will recur once in six years and the years will be arranged in the vertical columns in the various tables counting by six in each column until a leap year or a year divisible by four without a remainder is reached. For instance, the first year in the column B of table e is 1800, the next 1806 and the next 1812, which latter was leap year and is underscored. In the months January and February, 1812, certain days of the month fell on Wednesday, but as an additional day is added to the month of February in leap year, days of the month after February which would otherwise fall on VVednesday, will occur a day later in the week, viz: Thursday and for this reason the year 1812 will be duplicated in the column B of the next table opposite the word Thursday and will then be marked with a star to indicate that when it is desired to find out on what day of the week a certain day of the month occurred,

The various tables are p the page containingthe leap year marked with a star must be used,the table containing the leap year with the underscore being used'for the months of January and February. Thus by using the arrangement of table 6, it will be seen that the first day of January, 1812, occurred on Wednesday. Were this arrangement in table e used for a month succeeding February, say for example October, it would indicate that October 1 occurred on Wednesday which would be incorrect, because the occurrence of February 29, 1812, would cause October 1 to come one day later in the week than it otherwise would. By using the arrangement in table f, it will indicate that Ootober 1,1812, occurred on Thursday. The year 1812 being leap year, the next year indicated in column B of table 6 will be five years later instead of six, viz: 1817. After 1817, 1823 (six years later) is indicated in column B table e. After 1823, 1828 is placed in column B, 1828 being a leap year indicated in a corresponding position in column B table cl and is marked with a star. After 1828, 183a (six years later) appears in column B table 6.

The manner above explained of arranging the years will be followed throughout the calendar and will be found to be accurate.

To ascertain on what day of the week a certain predetermined day of the month in a certain year occurs, the following directions should be observed: Find the year required. On the left will be the days of the week for that year except leap years which have two places.

Use the Week days on the left of the leaf of the leap years marked with an underscore until March 1. For the rest of the year use the one marked with the star on the'following leaf or table. Turn the leaves having the months marked thereon as desired. For any year notgiven increase ordiminish those already given by four hundred. The device will preferably be made with a perforation h for the reception of astring or other'device by means of which to hang it up.

Instead of arranging the monthly calendars and the days of the week as shown in Fig. 1 they may be arranged as shown in Fig. 9 in which construction the book is simply turned around with the days and dates extending lengthwise the book instead of across it as in the other form.

Other slight changes might be made in the arrangement of the parts of the device and in the details of construction without departing from the spirit of my invention or limiting its scope and henceI do not wish to limit myself to the precise details of construction herein set forth, but,

Having fully described my invention, what I claim as new, and desire to secure by Letters Patent, is

1. A perpetual calendar consisting of a series of tables containing figures indicating a series of years and also containing the names of the days of the week so arranged that they can be read in regularorder on each table and also across the series of tables and a series of monthly calendars adapted to be read with any of said tables, substantially as set forth.

2. In a perpetual calendar, the combination with a cover, of a series of monthly calendars made in the form of a book and secured in said cover, a series of tables containing the dates of the days of the week and several HENRY S. STEVENS.

Witnesses:

M. W. BOND, JOHN H. MATTHEWS. 

